Yes, most of these things happen.
But in my experience, a few buyers do this. However, because the system is set up to almost always favor the buyer, the seller ends up at the receiving end.
This shouldn't be the case. If a buyer keeps delaying requesting a revision or is unsure about what they want, the seller shouldn't be made to suffer for it.
I advise focusing on delivering quality service and ensuring that you and the buyer are always on the same page. You're still going to attract buyers who will misuse the revision request feature, but in the long run, you will win.
But please, never make "dummy" deliveries. It will put you trouble.
Let's keep pushing!